Abstract:
This data set contains imagery from the National
Agriculture Imagery Program (NAIP). The NAIP
acquires digital ortho imagery during the
agricultural growing seasons in the continental U.S.
A primary goal of the NAIP program is to enable
availability of ortho imagery within one year of
acquisition. The NAIP provides two main products: 1
meter ground sample distance (GSD) ortho imagery
rectified to a horizontal accuracy within +/- 5 meters
of reference digital ortho quarter quads (DOQQ's) from
the National Digital Ortho Program (NDOP) or from the
National Agriculture Imagery Program (NAIP); 1 meter
GSD ortho imagery rectified within +/- 6 meters to
true ground. The imagery may contain as much as
10% cloud cover per tile.
The tiling format of the USDA_FSA NAIP imagery is
based on a 3.75' x 3.75' quarter quadrangle with a 300
meter buffer on all four sides. These quarter quads are
mosaicked into seamless countywide products, rectified
to the UTM coordinate system (NAD83) and compressed to
MrSID (with a compression ratio of 15:1). The county
mosaics comprise the source imagery for the product
GRANIT is distributing.
GRANIT re-processed the countywide mosaics to:
1) re-project the data to NH State Plane feet, NAD83;
2) mosaic the county files into a statewide image;
3) tile the data to 15-minute quadrangles to facilitate
distribution; and
4) re-compress the data to MrSID Generation 3 format using
a 50:1 compression ratio.